Various forms of holders for holding the mouth of a plastic garbage bag open are known. Such holders conventionally comprise a stiff bow-shaped member defining an opening, a straight portion of the member being adapted for mounting to a vertical surface. The top of the bag is located in the opening and the end of the bag folded over the member. A bow-shaped rod or band is often provided to hold the bag in place and is typically pivoted to the rear of the straight portion of the member and is moveable to a position where the rod frictionally engages the bag between the rod and the exterior of the member. Such holders tend to be of relatively heavy construction and consequently are difficult to transport, handle and mount.